I have just thrown in the towel after 10 years with Leica M8 and M9,,, initiated by the launch of Nikon Z7 but when I got the D850 in my hands I could no put it down again, Wow it's truly a luxury upgrade from D810 and I hope it will revive my fun with Nikon and Nikkors
Leica M system is amazing if you can afford/find the good/expensive lenses that fit your style, and yes it's countless times I have run out of close up options with it,,, I had the sweet 105mm f/2.5 Leica Thread mount version, but again then your approaching the focal length maximum for mechanical rangefinder reliability also already at 105mm,,,
High ISO is not possible even with the latest M10
Since i'm not a Video guy, It's quite seldom I have quotes for it, and for that the D850 is quite capable 4K Full Frame video and the Zacuto Pro finder does the job nicely.
So now all Leica M is sold, luckily it retains the value over time, quite amazing I got the same money for the M9 as I paid 4 years agoSo actually have cash to spend,,, as if I needed more lenses, just found a made in Japan 50mm AF-D f/1.4 that I look forward to take through its paces